The effect of concurrent tumour bed boost delivery on acute and late toxicity in patients with breast cancer: update of a systematic review.

Abstract

Purpose/Objective(s): The aim of this study was to provide an update on a previously published systematic review focusing on rates of acute and late toxicity associated with the integration of tumour bed boosts into whole breast irradiation for patients with Stage 0-III breast cancer. Materials/Methods: A comprehensive systematic electronic search through the Ovid MEDLINE, EMBASE, and PubMed databases was repeated in April 2016. Studies were deemed eligible if they investigated the toxicity of whole breast irradiation with a daily concurrent tumour bed boost. The primary outcomes of interest were the rates of acute and late toxicity during and following radiation therapy treatment. The secondary outcome of interest was late cosmesis. Methodological quality assessment was conducted on all included studies using either the Newcastle-Ottawa Scale or a previously published investigator-derived quality instrument. Results: The updated search identified 13 articles published since January 2015, of which 4 cohort studies and 3 case series were eligible for incorporation into the review. Seven and six studies reported on acute and late toxicities respectively. Following integration of results, rates of grade 3 acute skin toxicity and moderate to severe fibrosis and telangiectasia remained limited to 7% and 9% respectively. Included studies were predominantly found to be of a low methodological quality. Conclusion: Studies investigating the integration of tumour bed boosts into whole breast radiation therapy continue to report short to medium-term toxicity profiles and cosmesis rates comparable to historical data at similar time-points. Whilst the length of follow-up and the quality of evidence underpinning these findings remains low, sufficient data have been generated to demonstrate the safety of concurrent tumour bed boost approaches.